Focusing on the body fat around the waist is more important than what the scales say when it comes to lowering the risk of obesity and type 2 diabetes, researchers have said. A team from the Carnegie School of Sport at Leeds Beckett University says the current method, measuring Body Mass Index (BMI), is not entirely accurate. BMI is calculated by dividing weight in kilograms (kg) by the height in metres (m) then dividing the answer again by the height. But, now it is thought working out a person’s waist-to-height ratio is far more accurate in predicting future metabolic diseases, obesity and type 2 diabetes. Michelle Swainso, senior lecturer in exercise physiology at Leeds Beckett, said: “The conventional measurement of obesity used by GPs is BMI. Although there are benefits to this method, there is concern that a lot of people are being classified as obese by BMI when they are not or are being missed by this classification when they need to be referred for help. “This is most definitely the case when people have a ‘normal’ BMI but high abdominal fat that is often dismissed.” The researchers wanted to find a better way to measure obesity in individuals so decided to try different measurements. Using 81 people they pitted BMI, waist circumference, waist-to-hip ratio, waist-to-height ratio and waist-to-height ratio against one another.

The findings showed that 36.5 per cent of the trial’s participants would be classed as obese if fat from the entire body was taken into account, rather than using BMI. Swainson said: “Carrying fat around the abdominal area has been shown to be an independent predictor of all-cause mortality in men and women. Put simply, it is more important, especially for cardio-metabolic conditions, that your belt notch goes down than the reading on the scales.” Dr Swainson said by introducing the “alternative and more accurate” waist-to-height ratio into clinical settings “more men and women would potentially be referred to programmes, such as weight management, to receive help in improving their health.” She added: “Even in a small sample of adults, our results provide further evidence that alternative measures are fundamental to the more accurate identification of obesity, therefore ensuring that individuals are referred to the most suitable therapeutic approach to reduce risk of obesity-related conditions.” The study was published in the PLOS One journal.